Four-stroke internal combustion engines are known. Typically, these engines run on either a spark ignition fuel (“SI fuel”), such as gasoline, or a compression ignition fuel (“CI fuel”), such as diesel fuel. The primary difference between CI fuels and SI fuels is the range of boiling points, otherwise known as a distillation curve and the ignition temperature. CI fuels have distillation curves above 150° C. and ignition temperatures of approximately 250° C. Exemplary CI fuels include diesel fuel, JP8, JP5, Jet-A, and kerosene. Standard automotive diesel fuel has a distillation curve in the range of 180° C. to 360° C. with an ignition temperature of approximately 250° C. SI fuels have distillation curves starting below 150° C. and ignition temperatures in the range of approximately 300° C. to 500° C. An exemplary SI fuel is premium automotive gasoline which has a distillation curve in the range of 25° C. to 215° C. with an ignition temperature of approximately 400° C.
Engines which utilize SI fuels are often used for smaller applications because such engines are generally lower cost, create less noise and vibration, do not require as heavy duty of components thereby reducing the size and weight, and typically have a higher speed range resulting in less shifting required during operation of a vehicle. Engines which utilize CI fuels are generally used for larger applications and include heavier duty components and offer the advantage of increased fuel economy, engine lifespan, and specific torque output.
Engines utilizing a CI fuel typically have a compression ratio in the range of 12:1 to 22:1. The term compression ratio as used herein being defined as the ratio of maximum volume of the combustion chamber (when the piston is at its farthest location from a top portion of the combustion chamber or the bottom of its stroke) to the minimum volume of the combustion chamber (when the piston is at its closest location from a top portion of the combustion chamber or at the top of its stroke). Engines utilizing a SI fuel typically have a compression ratio in the range of 8:1 to 12.5:1. Low power, air cooled engines and industrial engines that utilize a SI fuel are known to have compression ratios as low as 6:1.
Situations arise wherein the fuel source available does not match the fuel type required by an engine. For example, during military campaigns many different types of vehicles are often employed, some having internal combustion engines that require gasoline and some having internal combustion engines that require diesel fuel. As the campaign continues these vehicles often travel to locations more and more remote from the main fuel supply of either gasoline or diesel fuel. As such, fuel transports, such as tanker trucks, must carry the fuel supply to the remotely located vehicles for refilling a fuel tank on the vehicle. If the remotely located vehicles include both gasoline powered vehicles and diesel powered vehicles, then both gasoline and diesel must be carried by the tanker trucks. This often results in requiring additional tanker trucks, some to transport gasoline and some to transport diesel fuel.